1. Field of the Invention
The present invention is generally related to a cooling system for an outboard motor and, more particularly, to a system that causes additional air flow through the enclosure of an outboard motor to provide additional cooling of an engine.
2. Description of the Related Art
Those skilled in the art of outboard motors are familiar with the various techniques for controlling the air flow into the space under a cowl of the outboard motor. Typically, air is directed from a location outside of the cowl of an outboard motor, through an opening and into the space under the cowl. That air is directed into the region surrounding the engine of the outboard motor and, eventually, into the air intake manifold of the engine.
U.S. Pat. No. 5,445,547, which issued to Furukawa on Aug. 29, 1995, describes an outboard motor having an engine compartment covered by an engine cover at its top portion and having an engine disposed within the engine compartment with its crankshaft directed in the vertical direction, in which charging efficiency of the engine is improved with a simple structure and a shielding property of the entire surrounding of the engine is also enhanced. A suction chamber communicating with an intake section of the engine is disposed on a surface other than the top surface of the engine and on one side of the inside of the engine compartment, an air intake port is provided in the engine cover at a position close to the other side of the inside of the engine compartment, an air exhaust port is provided in the engine cover, and a duct is provided within the engine compartment for leading air from the air intake port towards the suction chamber while making a detour to avoid a route above the engine.
U.S. Pat. No. 5,937,818, which issued to Kawai et al. on Aug. 17, 1999, describes a ventilation system for an outboard motor. An engine has an output shaft arranged to drive the propulsion device. The ventilating system includes an air inlet in the cowling which permits air to flow into an engine compartment in which the engine is positioned, and an exhaust port positioned in the cowling. The system also includes a mechanism for drawing air through the inlet into the compartment and expelling air out of the compartment through the exhaust port after the engine has stopped.
U.S. Pat. No. 5,996,546, which issued to Kollmann et al. on Dec. 7, 1999, discloses an integrated flywheel cover and air conduit passage. A cover for an outboard motor is provided to protect an operator from a flywheel. The cover is disposed under the cowl of the outboard motor. The cover is made of a generally rigid material, such as plastic, with first and second sheets being associated together to form conduits with openings extending therefrom. In one particular embodiment, one of the openings is shaped to receive an inlet of a compressor and thus provides a positioning aid in attaching the cover to the engine. This device eliminates the need for flexible hoses and accomplishes two tasks with one component. It provides air conduits for the air passing through the cover and it provides a generally rigid means for locating the proper location of the cover.
U.S. Pat. No. 6,024,616, which issued to Takayanagi on Feb. 15, 2000, describes an engine cover of an outboard motor. The outboard motor includes an engine which is covered by an engine cover which is formed with a cylindrical air suction port having an opening opened to an upper surface of the engine cover in a state of the outboard motor mounted to a hull, and a portion of an opening area of the opening is covered by a lid member which is formed to a rear edge portion of the opening.
U.S. Pat. No. 6,413,131, which issued to Phillips et al. on Jul. 2, 2002, discloses an air flow system for an outboard motor. The outboard motor is provided with an air duct located within the cavity of a cowl of an outboard motor. The air duct defines a chamber within it in association with first and second openings that allow heated air to flow, through the creation of convection currents, out of the engine compartment under a cowl. This convection flow removes heat from fuel system components and reduces the likelihood that “vapor lock” will occur subsequent to the use of an internal combustion engine that is followed by turning the engine off.
U.S. Pat. No. 6,899,579, which issued to Bruestle on May 31, 2005, discloses a marine propulsion device with variable air intake system. An air flow control mechanism is provided to control the flow of air through an opening formed in a portion of a cowl of an outboard motor. The air flow control mechanism is configured to be movable between a first position and the second position to affect the magnitude of air flowing through an air passage defined as being the space between the opening formed in the cowl and an exit through which the air can leave the cavity of the cowl. The airflow control mechanism can control the flow of air as a function of an operating characteristic of the engine, such as its operating speed, the load on the engine, or the operating temperature of the engine.
The patents described above are hereby expressly incorporated by reference in the description of the present invention.
It would be significantly beneficial if a system could be provided that improves the circulation of air through the space under a cowl of an outboard motor and which does not rely solely on the natural movement of the air under the influence of convention currents, or the forward movement of the outboard motor, when an associated marine vessel is being operated on a body of water.